The far-infrared (FIR) region of the spectrum (10-500 cm-1) is a hitherto unexplored region for ultrafast spectroscopy of biological systems. However, the rapidly advancing field of terahertz spectroscopy is making such experiments possible. Optical rectification of an optical pulse (typically 800 nm) in a suitable nonlinear crystal such as GaAs produces a sub-single-cycle electromagnetic pulse of radiation with Fourier components on the order of a few terahertz (1 THz = 33 cm-1). If a sufficiently short optical pulse (> 20 fs) is used, the bandwidth of the resulting pulse can be as large as 1000 cm-1. We have assembled the primary part of a source for terahertz pulses, a detector and an interferometer. The source will produce terahertz radiation in the range of 0-200 cm-1. This is precisely the most unexplored region of the protein motions. This terahertz source will be designed to interface with pump/probe techniques using visible and UV radiation.